Is this possible?

[Space cat]

You should start by finding the other end of that three core + earth cable. Does it go to the ceiling rose or, more likely, direct to the double switch? If there's a neutral connection available in that double switch box AND the three core cable goes direct to the single switch, you can use two of its three cores as live and neutral supply for your outside light. In the unlikely event that the three core cable goes to the rose you can work the same trick. Permanent live and neutral should be up there. All of this is highly speculative and you probably won't be that lucky.

 

[Droo]

Had a look this morning at the double switch.

There are 4 cables (3 core and Earth) going into it.

Am I ok to assume that they would be....

1 from the single switch
1 from one light
1 from the other light
1 from the next room

Here is a pic...

All the neutrals are together in the block.

The black and grey are sleeved brown. I think this is the cable to the single switch as I have black, grey and brown there.

There is a loop from L1 to L2 at the top too.

 

[Space cat]

All of this is highly speculative and you probably won't be that lucky.

It looks very much like you are that lucky! The picture helps a lot but it's not easy to see exactly what's in each terminal. It would help if you could give us a definitive list of all the cables coming into the box, what colour cores they have and which terminals they go to.

From what I can see, I'd say that the right hand switch in your picture is the two way one. Its three terminals are L1 at the bottom and L2/L3 at the top. L1-top belongs to the other switch and appears to have three brown wires in it. I would expect these to be permanent live. L3-bottom should be switched live for one of your lights and L3-top should be switched live for the other. Everything points to that choc block being full of neutrals. Are there four blue wires in there?

 

[Droo]

It turns out that there are 5 cables.

4 are 2 core and earth. 1 is 3 core and earth, pretty sure this goes to the single switch.

All blue go into a block and all earth cables are together.

That leaves...

Cable 1 - Brown - L1 (Top)
Cable 2 - Brown - L1 (Top)
Cable 3 - Brown - L2 (Bottom)
Cable 4 - Brown - L3 (Top)
Cable 5 - Grey - L2 (Top), Black - L3 (Top), Brown - L1 (Bottom)

There is a brown wire looped from L1 to L2 at the top.

 

[Droo]

Any ideas Space Cat?

Or anyone else?

 

[Space cat]

Yes indeed. I would have got back earlier but today was a mad, mad, mad, mad day!

Cables one and two are permanent live and neutral. One brings power in and the other takes it on to the next light. Keep their browns tied together or other lights will stop working. Note that we don't know which one is the supply at this point and it doesn't really matter.

Cable 3 is switched live to one of your lights. Leave this one where it is.

Cable 4 is switched live to the other light. Move its brown wire to L1 bottom.

Cable 5, as you suspect, goes to the single switch. Remove all three cores and put them in choc block for now but be sure you know where they came from just in case you have to put everything back and start again.

You should now have two lights controlled by the two switches in that double. All other lights should work as before. If this is the case you can be 99.9% sure that the three core cable is isolated but I prefer 100%. Connect its three cores together then connect a light bulb between them and the neutral block. Switch the two lights on. If the extra bulb lights up my final 0.1% is vindicated - but it won't.

At the single switch end, put brown and black into Live In and Neutral In on a new, fused, two pole switch. Sleeve the black with blue and isolate grey. Back at the double switch, put the brown core into L2 top. Sleeve the black one blue and put it into the neutral block. Isolate the grey one. You can now connect your outside light to the other side of the fused switch.

 

[Droo]

Thanks for your reply Space Cat, really appreciate your help!

I did as you said and everything worked as you said it would.

I plan to go and buy everything at the weekend and fit the light.

Just to make sure I get the right switch are these what you are talking about...

http://www.screwfix.com/search.do;j...HZOSFFQ?_dyncharset=UTF-8&fh_search=dp+fcu+sw

Also I have some 0.5mm cable left over from something else, even though it said on the pack it can be used for up to 240v am I better off using 1.0mm or 1.5mm to connect the light to the switch???

I'll let you know how I get on!

 

[JohnD]

0.5mm cable is too thin for lighting circuits. it won't carry enough amps. use 1.5mm cable.

Avoid cheap brands of switch. MK, Crabtree and MEM are good and any deaer or shed should carry one of them, as well as some cheap rubbish for people who don't know better.

IMO MK are the most elegant of the plain white ranges.

If you buy fancy brass or coloured ones, they are more expensive so it is even more important to buy a good brand.

 

[Space cat]

JohnD is quite right about the cable. At 0.5 sq mm it wouldn't be proper mains cable anyway. Quite apart from the size, a mains cable should be instantly recognizable as such.

If you get a switch with a neon on it you'll know whether your outside light is on or off without having to go out and look.

 

[alpcon]

My god!!! Not meaning to be rude but it seems from this thread that Droo hasn't a clue what he is doing and i expect this will be his last post on this forum as someone will find a black shriveled shape hanging from the ceiling.

Please get an electrician to do the job and live another day!!!

 

[Steve]

My god!!! Not meaning to be rude but it seems from this thread that Droo hasn't a clue what he is doing and i expect this will be his last post on this forum as someone will find a black shriveled shape hanging from the ceiling.

Please get an electrician to do the job and live another day!!!

You aint seen nothing mate.

 

[Droo]

All done.

No problems encounted and all working as it should.

Thanks for your help Space Cat.

 

[Space cat]

You're welcome.